Low noise frequency combs and injection locking for broadly tunable laser sources and tomography
Doctoral thesis, 2023

Lasers have revolutionized the world of physics by providing a highly coherent source of photons which may be used for a large variety of purposes. Here, we study the noise properties of frequency combs - a special class of frequency stabilized and mutually coherent multi-mode lasers, as well as the optical injection locking of comb tones as a means for low noise amplification and tone selection. A variety of applications are discussed, along with more fundamental properties of the systems in question. Particular focus is placed on the exceptionally low phase noise of these sources.

Several comb sources are investigated, including bulk electo-optic combs, on-chip anomalous dispersion micro-combs, and on-chip normal dispersion photonic molecules. Similarly, several sources are investigated for their use in optical injection locking, including DFB slave laser arrays, and multi-mode FP lasers. Noise mitigation is also investigated at length, with a focus on PID control loops and thermorefractive noise reduction at high temperature. Furthermore, significant attention is given to the noise analysis of frequency combs and optical injection locking. The mutual coherence of comb tones is investigated, along with the growth of noise as a function of comb mode index. Finally the role of injected noise is studied in the case of optical injection locking near the limit of stability for locking.

relative intensity noise

frequency comb

frequency noise

phase noise

optical injection locking

Kollektorn
Opponent: Prof. Periklis Petropoulos

Author

Connor Skehan

Chalmers, Microtechnology and Nanoscience (MC2), Photonics

Phase locked, pre-amplified optical injection locking at low input powers

Soliton microcomb based spectral domain optical coherence tomography

The generation of highly coherent photon sources is of vital importance for developing various fields of science - especially in communications, metrology, and spectroscopy. As such, the noise properties of lasers are studied in detail throughout these fields. Here, we’re interested in very low noise optical frequency combs – a special class of multi-mode laser defined by their many mutually coherent and equally spaced frequencies, and in optical injection locking as a means of low noise amplification of laser light. Similarly, we investigate several applications of these technologies, and several ways to improve the noise properties of these devices.

Areas of Advance

Nanoscience and Nanotechnology

Subject Categories

Atom and Molecular Physics and Optics

Other Physics Topics

Infrastructure

Nanofabrication Laboratory

ISBN

978-91-7905-964-4

Doktorsavhandlingar vid Chalmers tekniska högskola. Ny serie: SSN0346-718X

Publisher

Chalmers

Kollektorn

Opponent: Prof. Periklis Petropoulos

More information

Latest update

12/5/2023